Pharmacokinetic and pharmacodynamic study of 3 products of epoetin alfa as single subcutaneous dose in healthy volunteers.

BACKGROUND: Hemax® is an epoetin alfa product developed by Biosidus S.A. in Argentina at the end of the 1980's and has been present in that market since 1991. The initial presentation was a lyophilized powder containing albumin as stabilizer, to best adapt to environmental conditions in developing countries; more recently, a prefilled syringe, albumin-free presentation was developed, since this presentation has become the preferred standard in many markets.

OBJECTIVE: The primary objective was to compare the pharmacokinetic profile of different formulations of epoetin alfa after a single subcutaneous administration to healthy volunteers of 40,000 IU of Eprex/Erypo® and Hemax® PFS.

METHODS: This clinical trial was conceived following an open label, randomized, 3-way 3-period cross-over balanced, and sequential design. The study was conducted on 24 healthy volunteers.

RESULTS: To analyze similarity between Hemax® PFS and the innovator product, Eprex®, AUC and Cmax of both products have been compared. The 90%CI lower limit for the geometric mean ratios was higher than 80% for any comparisons and the 90%CI upper limit for these geometric ratios was below 125% for all the comparisons made, thus demonstrating equivalence between both products.

CONCLUSION: The comparison between Hemax® PFS and Eprex® resulted in similar 90%CI for Cmax , AUC(0-120 h) and AUC(0-inf) ratios, all of them within the 80-125% interval, with a power above 95% for each ratio. These findings suggest biosimilar patterns for absorption velocity (with Tmax close to 15 h), absorption extent and elimination (with an elimination half-life close to 25-30 h for each formulation).